Two-dimensional material and preparation method therefor

Abstract

A two-dimensional material and a preparation method therefor. The preparation method comprises: preparing a sample component to be treated in a target temperature range, wherein said sample component comprises a metal substrate and a two-dimensional material, the two-dimensional material is located on the surface of the metal substrate, and the target temperature range is a temperature range when the two-dimensional material is free of wrinkles on the metal substrate; and removing the metal substrate in the target temperature range to obtain the wrinkle-free two-dimensional material. When a two-dimensional material is prepared, a sample component to be treated is obtained, said sample component being at a target temperature, and the two-dimensional material being free of wrinkles at the target temperature, and then a metal substrate continues to be removed at the target temperature.

Description

A two-dimensional material and preparation method thereof

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on November 16, 2023, with application number 202311533657.X and invention name “A two-dimensional material and its preparation method”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of material preparation, and in particular to a two-dimensional material and a preparation method thereof. Background Art

[0003] At present, when preparing graphene or graphite film, we can take advantage of the principle that the high carbon solubility of the metal substrate at high temperature will precipitate carbon when the temperature is lowered, and that the carbon atoms in the solid two-dimensional material growth source at high temperature will continuously generate graphite on the metal surface through isothermal dissolution and diffusion from the solid two-dimensional material growth source, so as to grow graphene or graphite film on a high-carbon soluble metal substrate.

[0004] Due to the significant difference in thermal expansion coefficients between the metal substrate and graphite, noticeable wrinkles appear on the surface of the film after it cools to room temperature. This is because the metal's high thermal expansion coefficient causes it to expand more than graphite at high temperatures, but when cooled, the metal contracts even more, causing significant wrinkles in the film grown on it. The presence of wrinkles severely limits the properties and application scenarios of graphite grown on metal substrates. Furthermore, many applications require the use of graphene or graphite film alone without a metal substrate, and removing the metal substrate using low-temperature wet etching cannot eliminate the wrinkles.

[0005] Therefore, how to solve the above technical problems should be the focus of those skilled in the art.

[0006] Summary of the Invention

[0007] The purpose of this application is to provide a two-dimensional material and a preparation method thereof to obtain a separate, wrinkle-free two-dimensional material.

[0008] To solve the above technical problems, the present application provides a method for preparing a two-dimensional material, comprising:

[0009] Preparing a sample component to be processed within a target temperature range; the sample component to be processed includes a metal substrate and a two-dimensional material, the two-dimensional material is located on the surface of the metal substrate, and the target temperature range is the temperature at which the two-dimensional material is wrinkle-free on the metal substrate;

[0010] The metal substrate is removed within the target temperature range to obtain the wrinkle-free two-dimensional material.

[0011] Optionally, preparing the sample parts to be processed at the target temperature range includes:

[0012] placing the metal substrate on the surface of a solid two-dimensional material growth source;

[0013] Under a protective gas, the metal substrate and the solid two-dimensional material growth source are heated to the target temperature range to grow the two-dimensional material on the surface of the metal substrate facing away from the solid two-dimensional material growth source, thereby obtaining the sample component to be processed.

[0014] Optionally, preparing the sample parts to be processed at the target temperature range includes:

[0015] The two-dimensional material is catalytically grown on the metal substrate by a gaseous two-dimensional material growth source within a target temperature range.

[0016] Optionally, preparing the sample parts to be processed at the target temperature range includes:

[0017] Obtaining a prefabricated sample component; the prefabricated sample component includes the metal substrate and the two-dimensional material, and the two-dimensional material has wrinkles;

[0018] The prefabricated sample component is heated under a protective gas to make the two-dimensional material into a flat two-dimensional material, thereby obtaining the sample component to be processed.

[0019] Optionally, the protective gas includes a reducing gas.

[0020] Optionally, also include:

[0021] The temperature is lowered to room temperature under protective gas, and the two-dimensional material is taken out from the preparation equipment.

[0022] Optionally, the metal substrate is a metal sheet with a flat surface, catalytic activity, a high melting point and a high carbon solubility.

[0023] Optionally, removing the metal substrate within the target temperature range includes:

[0024] Completely remove the reducing gas in the preparation equipment;

[0025] A reaction gas is introduced, and the reaction gas reacts with the metal substrate to completely etch the metal substrate.

[0026] Optionally, the reaction gas includes at least one of chlorine, bromine, hydrogen chloride, hydrogen bromide, and fluorine-containing gas.

[0027] Optionally, the reaction gas includes chlorine and argon.

[0028] The present application also provides a two-dimensional material, which is prepared using any of the two-dimensional material preparation methods described above.

[0029] A method for preparing two-dimensional materials provided in the present application includes: preparing a sample part to be processed that is within a target temperature range; the sample part to be processed includes a metal substrate and a two-dimensional material, the two-dimensional material is located on the surface of the metal substrate, and the target temperature range is the temperature when the two-dimensional material is wrinkle-free on the metal substrate; removing the metal substrate within the target temperature range to obtain the wrinkle-free two-dimensional material.

[0030] As can be seen, in this application, when preparing a two-dimensional material, a sample component to be processed is obtained, and the sample component to be processed is placed in a target temperature range, within which the two-dimensional material is wrinkle-free. Then, the metal substrate is removed within this target temperature range. This application not only removes the metal substrate to obtain a separate two-dimensional material, but also performs the metal substrate removal process within the target temperature range, avoiding wrinkles caused by the difference in thermal expansion coefficients between the metal substrate and the two-dimensional material after cooling, thereby obtaining a wrinkle-free two-dimensional material.

[0031] In addition, the present application also provides a two-dimensional material having the above advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present application or the technical solutions of the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0033] FIG1 is a flow chart of a method for preparing a two-dimensional material provided in an embodiment of the present application;

[0034] FIG2 is a second flow chart of a method for preparing a two-dimensional material provided in an embodiment of the present application;

[0035] FIG3 is a schematic diagram of a method for preparing a two-dimensional material provided in an embodiment of the present application;

[0036] FIG4 is a flow chart 3 of a method for preparing a two-dimensional material provided in an embodiment of the present application;

[0037] FIG5 is a second schematic diagram of a method for preparing a two-dimensional material provided in an embodiment of the present application;

[0038] In the figure, 1. Solid-state two-dimensional material growth source, 2. Metal substrate, 3. Two-dimensional material. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments. Obviously, the embodiments described are only a part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making any creative efforts are within the scope of protection of the present application.

[0040] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0041] As mentioned in the background section, the significant difference in thermal expansion coefficients between the metal substrate and graphite causes wrinkles on the surface of the film after cooling to room temperature. This wrinkling severely limits the properties and applications of graphite grown on metal substrates. Furthermore, many applications require the use of graphene or graphite films alone without a metal substrate, and low-temperature wet etching to remove the metal substrate does not eliminate the wrinkles.

[0042] In view of this, the present application provides a method for preparing a two-dimensional material. Please refer to FIG1 . The method includes:

[0043] Step S101: preparing a sample component to be processed within a target temperature range; the sample component to be processed includes a metal substrate and a two-dimensional material, the two-dimensional material is located on the surface of the metal substrate, and the target temperature range is the temperature when the two-dimensional material is wrinkle-free on the metal substrate.

[0044] The thickness of the two-dimensional material prepared in this embodiment ranges from several nanometers to tens of micrometers. The two-dimensional material can be single crystal graphite, boron nitride, boron nitride / graphite or boron nitride graphene heterojunction, etc.

[0045] In this embodiment, the metal substrate is not specifically limited; any metal substrate having a high carbon solubility at high temperatures and capable of precipitating carbon upon cooling can be used. For example, the metal substrate can be a flat metal sheet having catalytic activity, a high melting point, and a high carbon solubility, including but not limited to nickel, platinum, palladium, iridium, gold, iron, or alloys thereof, with a purity greater than 99% by weight, preferably a single crystal nickel sheet or a copper-nickel alloy sheet.

[0046] The target temperature range is the growth temperature of the 2D material, at which the 2D material is wrinkle-free on the metal substrate. The target temperature range can vary depending on the type of metal substrate. For example, when the metal substrate is a nickel substrate or a copper-nickel alloy substrate, the target temperature range can be 1000°C to 1350°C, for example, 1000°C, 1100°C, 1200°C, 1300°C, 1350°C, etc.

[0047] It should be noted that the sample component to be processed also includes a solid two-dimensional material growth source, which is located on the surface of the metal substrate facing away from the two-dimensional material. For example, when the two-dimensional material is located on the upper surface of the metal substrate, the solid two-dimensional material growth source is located on the lower surface of the metal substrate.

[0048] Step S102: removing the metal substrate within the target temperature range to obtain the wrinkle-free two-dimensional material.

[0049] The preparation equipment used in the preparation method of the present application may be a tubular furnace, that is, the preparation process is carried out in a tubular furnace.

[0050] It should be noted that the wrinkle-free two-dimensional material in this application refers to a two-dimensional material with a wrinkle height of less than 1 micron. However, the wrinkle height of the two-dimensional material produced in the related art is generally between 10 microns and 100 microns. Furthermore, in one embodiment of this application, it may also include:

[0051] The temperature is lowered to room temperature under protective gas, and the two-dimensional material is taken out from the preparation equipment.

[0052] The protective gas includes a reducing gas, such as hydrogen, or hydrogen and argon, to prevent oxidation of the 2D material. Because the sample to be processed also includes a solid-state 2D material growth source, the solid-state 2D material growth source is also removed when the 2D material is removed from the preparation equipment.

[0053] In this embodiment, when preparing a two-dimensional material, a sample component to be processed is obtained, and the sample component to be processed is placed within a target temperature range, within which the two-dimensional material is wrinkle-free. The metal substrate is then removed within this target temperature range. This application not only removes the metal substrate to obtain a separate two-dimensional material, but also performs the metal substrate removal process within the target temperature range, avoiding wrinkles caused by the difference in thermal expansion coefficients between the metal substrate and the two-dimensional material after cooling, resulting in a wrinkle-free two-dimensional material.

[0054] Based on the above embodiment, in one embodiment of the present application, referring to FIG2 and FIG3 , a method for preparing a two-dimensional material includes:

[0055] Step S201: placing the metal substrate on the surface of a solid two-dimensional material growth source.

[0056] When the two-dimensional material is single-crystal graphite, the solid-state two-dimensional material growth source 1 includes but is not limited to graphite paper, graphite powder, and carbon black, and the metal substrate 2 is located on the upper surface of the solid-state two-dimensional material growth source 1. For other two-dimensional materials such as boron nitride, the boron source generally uses boron-containing compounds such as B(OCH3)3, BF3, B2H6, BBr3, and BCl3, and the nitrogen source is generally N2 or NH3, or directly using borazane.

[0057] Step S202: Under a protective gas, heat the metal substrate and the solid two-dimensional material growth source to the target temperature range to grow the two-dimensional material on the surface of the metal substrate away from the solid two-dimensional material growth source to obtain the sample component to be processed.

[0058] At high temperatures (within the target temperature range), atoms or molecules in the solid two-dimensional material growth source continuously generate corresponding two-dimensional materials on the surface of the metal substrate through isothermal dissolution and diffusion from the solid two-dimensional material growth source.

[0059] In one embodiment, the shielding gas includes a reducing gas, such as hydrogen. However, this application does not specifically limit this. In another embodiment, the shielding gas includes a reducing gas and at least one inert gas, for example, the shielding gas includes hydrogen and argon, or includes hydrogen and nitrogen, or includes hydrogen, nitrogen, and argon, etc.

[0060] As shown in FIG3 , the two-dimensional material 3 is grown on the upper surface of the metal substrate 2 .

[0061] The time for growing two-dimensional materials on a metal substrate can range from 1 hour to 100 hours, depending on the desired thickness of the two-dimensional material. The longer the growth time, the thicker the film.

[0062] When the metal substrate and the solid two-dimensional material growth source are heated to the target temperature range under a protective gas, the pressure is below 0.2 Pa.

[0063] In other embodiments, preparing the sample component to be processed at a target temperature range includes:

[0064] The two-dimensional material is catalytically grown on the metal substrate by a gaseous two-dimensional material growth source within a target temperature range.

[0065] That is, a gas source is used to grow the two-dimensional material. When the two-dimensional material is single crystal graphite, the gas two-dimensional material growth source can be a carbon-containing gas source such as methane, ethane, and acetylene.

[0066] Preferably, a solid carbon source is used to grow single crystal graphite.

[0067] The gaseous two-dimensional material growth source dissolves into the metal substrate at high temperature. Since the solubility of the two-dimensional material growth source in the metal substrate is different at different temperatures, when the temperature is lowered, the two-dimensional material will precipitate on the surface of the metal substrate due to the decrease in solubility.

[0068] Step S203: removing the metal substrate within the target temperature range to obtain the wrinkle-free two-dimensional material.

[0069] In this embodiment, when preparing a wrinkle-free two-dimensional material, after growing the two-dimensional material on a metal substrate, the metal substrate is directly removed in situ, so that the wrinkle-free two-dimensional material with the metal substrate removed can be obtained simply and efficiently.

[0070] Based on the above embodiment, in one embodiment of the present application, referring to FIG4 and FIG5 , a method for preparing a two-dimensional material includes:

[0071] Step S301: obtaining a prefabricated sample component; the prefabricated sample component includes the metal substrate and the two-dimensional material, and the two-dimensional material has wrinkles.

[0072] As shown in Figure 5, the prefabricated sample component in this embodiment consists of a component that has already grown a two-dimensional material 3 on a metal substrate 2 and then cooled. Due to the difference in thermal expansion coefficients between the metal substrate 2 and the graphite after cooling, wrinkles appear on the two-dimensional material 2. The prefabricated sample component also includes a solid-state two-dimensional material growth source 1.

[0073] The prefabricated sample may be a component manufactured on a metal substrate according to steps S201 to S202 and obtained after cooling, or may be a component manufactured by others.

[0074] Step S302: heating the prefabricated sample component under a protective gas to make the two-dimensional material into a flat two-dimensional material, thereby obtaining the sample component to be processed.

[0075] The prefabricated sample component is placed in a preparation device (such as a tube furnace) and heated. When the heating temperature reaches the target temperature range, the wrinkles on the two-dimensional material 3 disappear, and a wrinkle-free film appears on the metal substrate 2, as shown in Figure 5.

[0076] In one embodiment, the shielding gas includes a reducing gas, such as hydrogen. However, this application does not specifically limit this. In another embodiment, the shielding gas includes a reducing gas and at least one inert gas, for example, the shielding gas includes hydrogen and argon, or includes hydrogen and nitrogen, or includes hydrogen, nitrogen, and argon, etc.

[0077] Step S303: removing the metal substrate within the target temperature range to obtain the wrinkle-free two-dimensional material.

[0078] In this embodiment, when preparing a wrinkle-free two-dimensional material, the sample that has grown the two-dimensional material on a metal substrate and cooled down is heated to make the wrinkles on the two-dimensional material disappear, and the metal substrate is further removed to obtain a separate, wrinkle-free two-dimensional material.

[0079] Based on any of the above embodiments, in one embodiment of the present application, removing the metal substrate within the target temperature range includes:

[0080] Completely remove the reducing gas in the preparation equipment;

[0081] A reaction gas is introduced, and the reaction gas reacts with the metal substrate to completely etch the metal substrate.

[0082] Since the growth of two-dimensional materials on a metal substrate and the heating treatment of samples that have already grown two-dimensional materials on a metal substrate and cooled down must be carried out under a protective gas, the protective gas contains reducing gas (hydrogen), which will react with the reaction gas, so the reducing gas needs to be completely removed.

[0083] The reducing gas can be removed by stopping the introduction of the reducing gas (hydrogen) and using an inert gas (such as argon) to purge the reducing gas remaining in the pipeline.

[0084] The flow rate of the reaction gas may be 10 to 200 SCCM (Standard Cubic Centimeter per Minute). The reaction gas may etch the metal substrate for 0.5 to 5 hours, depending on whether the metal substrate is completely removed.

[0085] When the metal substrate is a nickel substrate or a copper-nickel alloy substrate, as an implementation method, the reaction gas includes at least one of chlorine, bromine, hydrogen chloride, hydrogen bromide, and fluorine-containing gas.

[0086] The product generated by the reaction gas and the metal substrate is a gas within the target temperature range, and the reaction product can be collected at the tail of the tube furnace.

[0087] The reaction gas is preferably chlorine gas, and the reaction products with the metal substrate, such as copper chloride and nickel chloride, have relatively low melting points and are easier to remove.

[0088] As an implementation method, the reaction gas includes chlorine and argon, wherein argon serves as a carrier gas.

[0089] The preparation method of the two-dimensional material in this application is further explained below.

[0090] Step 1: placing a metal nickel substrate on a solid carbon source;

[0091] Step 2: Pump the equipment to low pressure (below 0.2 Pa), raise the temperature to the graphite growth temperature in an argon and hydrogen atmosphere, generally 1000°C to 1350°C, and grow the single crystal graphite on the surface of the nickel substrate for 1 to 100 hours under this temperature and gas atmosphere;

[0092] Step 3: Turn off the hydrogen and use argon to purge the remaining hydrogen in the tube;

[0093] Step 4: Chlorine or a mixture of chlorine and argon is introduced to perform gas etching on the nickel substrate for 0.5 to 5 hours to completely etch the nickel substrate. The nickel chloride produced by the reaction is collected at the end of the furnace.

[0094] Step 5: Turn off the chlorine gas and use argon gas to purge the residual chlorine in the pipeline;

[0095] Step 6: introducing hydrogen to cool the single crystal graphite and the solid carbon source to room temperature in a mixed gas of argon and hydrogen;

[0096] Step 7: Turn off the gas, take out the sample, and the wrinkle-free single crystal graphite is prepared.

[0097] The preparation method of the present application is described below with reference to different embodiments.

[0098] Example 1: Place a nickel sheet on graphite paper and place the sample in a heated constant temperature zone. Pump the equipment down to a low pressure below 0.2 Pa, turn off the vacuum pump, introduce argon and hydrogen to atmospheric pressure, then open the tail gas vent valve. Raise the temperature to 1100°C in an argon and hydrogen atmosphere. Grow and process at this temperature and gas atmosphere for 72 hours. Turn off the hydrogen and use argon to purge any residual hydrogen in the tube. Introduce chlorine and etch at 1100°C for 3 hours in a mixed gas atmosphere of chlorine and argon to completely etch the nickel sheet. Collect the nickel chloride produced by the reaction at the end of the furnace. Turn off the chlorine and use argon to purge any residual chlorine in the pipeline. Introduce hydrogen and cool the sample to room temperature in the mixed gas of argon and hydrogen. Turn off the gas, remove the sample, and the sample processing is complete.

[0099] Example 2: Process the sample on which graphite has been grown on the nickel sheet, and place the sample in a heated constant temperature zone. Pump the equipment to a low pressure below 0.2 Pa, turn off the vacuum pump, introduce argon and hydrogen to normal pressure, and then open the tail gas vent valve. Raise the temperature to 1200°C in an argon and hydrogen atmosphere, turn off the hydrogen, and use argon to purge the residual hydrogen in the tube. Introduce chlorine gas, and etch at 1200°C for 2 hours in a mixed gas atmosphere of chlorine and argon to completely etch the nickel sheet. The nickel chloride produced by the reaction is collected at the end of the furnace. Turn off the chlorine gas, and use argon to purge the residual chlorine in the pipeline. Introduce hydrogen gas, and cool the sample to room temperature in the mixed gas of argon and hydrogen. Turn off the gas, take out the sample, and the sample processing is complete.

[0100] Implementation Case 3: For the treatment of samples on which graphite has been grown on nickel sheets, place the samples in a heated constant temperature zone. Pump the equipment to a low pressure below 0.2 Pa, turn off the vacuum pump, introduce argon and hydrogen to normal pressure, and then open the tail gas vent valve. Heat to 1300°C in an argon and hydrogen atmosphere, turn off the hydrogen, and use argon to purge the residual hydrogen in the tube. Pump to a vacuum, introduce chlorine to 0.01Mpa, then turn off the chlorine and hydrogen, close the air inlet and exhaust ports, turn off the vacuum pump, and etch at 1300°C for 1 hour in a low-pressure chlorine atmosphere to completely etch the nickel sheet. Then open the air inlet, open the argon gas and fill it to normal pressure, open the exhaust port, and use argon to purge the residual chlorine in the pipeline. Then introduce hydrogen to cool the sample to room temperature in a mixture of argon and hydrogen. Turn off the gas, take out the sample, and the sample processing is complete.

[0101] Implementation Case 4: Place a nickel sheet on a sapphire sheet and place the sample in a heated constant temperature zone. Pump the equipment down to a low pressure below 0.2 Pa, turn off the vacuum pump, introduce argon and hydrogen to atmospheric pressure, then open the tail gas vent valve. Raise the temperature to 1200°C in an argon and hydrogen atmosphere. At this temperature, introduce carbon source methane gas. Grow and process for 72 hours in an argon, hydrogen, and methane atmosphere. Then, turn off the hydrogen and methane, and use argon to purge any residual hydrogen and methane in the tube. Chlorine is introduced, and etching is performed at 1100°C for 3 hours in a mixed atmosphere of chlorine and argon to completely etch the nickel sheet. The nickel chloride produced by the reaction is collected at the end of the furnace. Turn off the chlorine, and use argon to purge any residual chlorine in the pipeline. Introduce hydrogen, and cool the sample to room temperature in the argon and hydrogen mixture. Turn off the gas, remove the sample, and sample processing is complete.

[0102] The present application also provides a two-dimensional material, which is prepared using the two-dimensional material preparation method described in any of the above embodiments.

[0103] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0104] The above is a detailed introduction to the two-dimensional material preparation method provided by this application. Specific examples are used herein to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of this application, several improvements and modifications can be made to this application, and these improvements and modifications also fall within the scope of protection of the claims of this application.

Claims

1. A method for preparing a two-dimensional material, It is characterized in that include: Prepare a sample component to be processed in a target temperature range; the sample component to be processed includes a metal substrate and a two-dimensional material, the two-dimensional material is located on the surface of the metal substrate, and the target temperature range is the temperature when the two-dimensional material has no wrinkles on the metal substrate; The metal substrate is removed within the target temperature range to obtain the two-dimensional material without wrinkles.

2. The method for preparing a two-dimensional material according to claim 1, It is characterized in that Preparing sample parts for processing at the target temperature range includes: placing the metal substrate on the surface of a solid two-dimensional material growth source; Under a protective gas, the metal substrate and the solid two-dimensional material growth source are heated to the target temperature range to grow the two-dimensional material on the surface of the metal substrate facing away from the solid two-dimensional material growth source, thereby obtaining the sample component to be processed.

3. The method for preparing a two-dimensional material according to claim 1, It is characterized in that Preparing sample parts for processing at the target temperature range includes: The two-dimensional material is catalytically grown on the metal substrate by a gaseous two-dimensional material growth source within a target temperature range.

4. The method for preparing a two-dimensional material according to claim 1, It is characterized in that Preparing sample parts for processing at the target temperature range includes: Obtaining a prefabricated sample component; the prefabricated sample component comprises the metal substrate and the two-dimensional material, and the two-dimensional material has wrinkles; The prefabricated sample component is heated under a protective gas to make the two-dimensional material a flat two-dimensional material, thereby obtaining the sample component to be processed.

5. The method for preparing a two-dimensional material according to claim 2, It is characterized in that The protective gas includes a reducing gas.

6. The method for preparing a two-dimensional material according to claim 1, It is characterized in that Also includes: The temperature is lowered to room temperature under a protective gas, and the two-dimensional material is taken out from the preparation equipment.

7. The method for preparing a two-dimensional material according to claim 1, It is characterized in that The metal substrate is a metal sheet with a flat surface, catalytic activity, high melting point and high carbon solubility.

8. The method for preparing a two-dimensional material according to any one of claims 1 to 7, It is characterized in that Removing the metal substrate at the target temperature range includes: Completely remove the reducing gas in the preparation equipment; A reaction gas is introduced, and the reaction gas reacts with the metal substrate to completely etch the metal substrate.

9. The method for preparing a two-dimensional material according to claim 8, It is characterized in that The reaction gas includes at least one of chlorine, bromine, hydrogen chloride, hydrogen bromide, and fluorine-containing gas.

10. The method for preparing a two-dimensional material according to claim 9, It is characterized in that The reaction gas includes chlorine gas and argon gas.

11. A two-dimensional material, It is characterized in that The two-dimensional material is prepared by the two-dimensional material preparation method according to any one of claims 1 to 10.

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